Sampling apparatus



- Aug. 20, 1946. w c. o. CANTRELL, JR 7 5,

v SAMPLING APFARATUS Filed Jan. 26, 1943 47 45 49 VAPOR I u l 48. 34 Y I I I I FIG. 2

FLOW L..I NE MANIFOLD c.o. CANTRELL. JR.

ATTORNEYS.

IN VEN TOR.

Patented Aug. 20, 1946 SAMPLING APPARATUS Cyrus D. Cantrell, Jr., Bartlesville, kla., assignor to Phillips Petroleum Company, a corporation of Delaware Application January 26, 1943, Serial No. 473,653

4 Claims. (Cl. 137F166) This invention relates to sampling and more particularly to obtaining representative samples of fluids being conveyed through conduits, and is a continuation-in-part of my prior filed application which mat ured as U. S. Patent No. 2,309,625, ,on Feb. 2, 1943.

It is often very desirable to know the amount of fluid being produced by a hydrocarbon oil well and the'quantity of each component part of that fluid. This knowledge is useful in determining eflicient production rates for a hydrocarbon oil well and is necessary for determining the amount of hydrocarbon'oil and gas reserves within a reservoir.

Standard practice is to produce a hydrocarbon oil well into a separation system consisting of an oil and gas separator and appropriate receivers, stock tanks, and the like, where oil, gas, and water are separated one from the other and the oil stored. If two or more wells produce into a single separation system or tank battery it is necessary to shut in all the other wells when it is desired to test one well. Shutting in the other wells may be undesirable because of difficulty in reviving flow, settling of sand in pumping equipment, and other common troubles, as Well as loss of production during the shut-in period. When testing of individual wells is of primary importance, a special testing system is provided. In the case of high pressure flowing wells, the complete test system requires a substantial investment in equipment even though necessary auxiliary vessels to the oil and gas separator are often omitted at the price of flexibility, accuracy, and safety. In either case it is often necessary to limit the length of the test to shorter periods than are necessary for most accurate results.

The practice of my invention simplifies the procedure of testing individual wells by installing a sampling device in the lease fluid conduit system between the well and the tank battery system. By cutting-out a representative sample of a predetermined fraction of the total fluid passing through the conduit, accurately testing that fraction and returning the same to the original volume, a well may be tested for any desirable length of time without interrupting the operations of the other wells producing into a central tank battery system. y i

' The present invention also eliminates the employment of duplicate systems of separators, re-

ceiving tanks, and/or storage tanks which are essential with the present methods of well testing where individual well tests are a necessary" operation and where all wells producing into a i central storage battery system must be produced continuously and Without interruption. The weight and space occupied by this complete sampling apparatus are such that the Whole is easily portable on a light truck or trailer and thus can be used' to serve several tank batteries for routine tests, or for special well-testing prob lems, and thereby eliminate the-permanent test equipment otherwise necessary. In the case of centralized tank batteries serving a large number of widely scattered wells, this device would eliminate long individual flow lines to that battery, or standard test equipment at the 'junction of each small group of flowlines.

The primary object of this invention is to 'provide an improved fluid sampling apparatus.

Another object is to provide an improved apparatus for taking a representative sample of fluid from a conduit.

A still further object is the provision of an improved apparatus for taking a representative sample of fluid produced from a hydrocarbon oil well, said sample being taken at some desirable point in a lease fluid conduit system for the purpose of testing component parts of the fluid. These and additional objects and advantages will be readily apparent to persons skilled in the art by reference to the following description and annexed drawing which pertains to' a preferred embodiment of my invention, and wherein Figure 1 represents a positive displacement type of device, partly in central longitudinal cross section, for obtaining representative fluid samples; and, y j

Figure 2 denotes a typical conduit and separation system for a group of hydrocarbon oil wells and having the sampling apparatus of Figure l ing samples of fluid as produced from a 'hydro-.

carbon oil well and as conveyed through the customary lease conduit system. It is to be understood that this is only one of the many usesito which thisdevice may be satisfactorily and economically applied in actual practice.

' Referring to Figure 1, I have illustrated therein a closed cylinder or chamber I that communicates with an inlet conduit 2 through a valve chest 3 and ports 4 and 5, alternately opened, and closed by a slide valve 6 fixed to a valve rodv 1 which is coupled to a crosshead8. Cylinder] also communicates with outlet or. exhaust cone.

chamber I through conduit 2-.

I9 is slidable with respect to member I8 and l crosshead 8. Member l8 carries a pair of latches -2I and 24 which are pivoted at 23 and'25, re-

spectively. Each of said latches is prdvidedlwith, a downwardly extending portion, that is adapted to engage notch 20 depending upon the relative position of member I8 and plate. I9; and an upwardly extending portion. A compression spring 22 tends to rotate latch 2| in a clockwise direction about its pivot point 23, while a similar spring ZE'tends to rotate; latch 24 ina. counter- CIOCKWZ ISG diIGCtiOHT about its pivot point 25,. ,As will be-noted froman examination of Figure: 1, member. I8 is so positioned with respect to plate I 9 that" the downwardly extending portion of latch: 21 has been received in notch. 29', whereas the corresponding. portion of. latch 24 rests on the-upper surface of plate: I9. A pair of preferablly coaxially disposed compressionsprings 21 and :28 are attached to member 58 and are adapted-to be alternately compressed by an arm 29l that'is secured tolvalve rod I'I.

fTur-ningnext' to-the system illustrated inFigure 2',I'have denoted therein a plurality of well flowlines 39, 3I, 32, and33, each of which com municates with-a separate producing oil well. A main flowline'34 connects with well flowlines 35, 3I', 32,:and 33 through valved branch lines 35, 37, 38, and 39, respectively. A test flowline 35 also connects with well flowlines 39, 3!, 32, and 33 through valved branch lines 49-, M; 42, and 43, respectively. Main flowline 34 discharges-into a tank battery hookup that'may be of any known design such as the illustrated arrangement of equipment which. consists in its essential elements of. a: gas-liquid'separator 44 that communicateswith a boot 45 which in turn communicates with. a plurality of stock tanks 46 that are connectedinxseries; 7 .Gas: thatis'separated from the-"well fluid in"; separator 441s taken off overhead through a line 41 as allowed-bye pressure regulator device-48.' Vapors evolved in boot 45 and stock tanks 43 are transmitted therefrom throughavapor-line49.

Testflowline. 35discharges into a battery conthe arrows; that both ends of th cylinder ar filled with well fluid; and, that the positions of the slide valves 6 and I4 are shown, with port 4 closed, port 5 open, port I3 closed, and port I2 open. The fluid entering conduit 2 is under substantially the same pressure as that existing in the test flowline 35 and causing the flow of fluid through it, and this pressure is exerted against the right-hand side of" piston I6; The pressure on the left-hand side of piston I6 is allowed to be less than that on the opposite side by adjustment of regulating valves 60 and 62, so that piston It moves toward the left. As the right-hand end of: thecyli'nder-fllls with fluid through conduit 2 theleft-hand end discharges fluid through conduit 9. arm. 29 engagesand. compresses spring 21.

Aspiston I6 moves toward the left,

Com-

pression of spring 21 continues until arm 29engages" and depresses the upwardly extending portion of latch 2|, thus compressing spring 22 and releasing; the downwardly extending portion of latch 2.! from notch At this. pointxm'ember I8 slides to the left on plate I9 moving crosshead 8, valve rods I and, I5, andslidevalves 6 and I4 to the left the distance d in Figure 1. When slide valves 6 and I4 have reachedv a position such that ports 4- and I3 are open; the downwardlyextending portion of latch 2-4. is forced to? drop into notch 20 by spring 26 and locks slidevalves 6 and I4, connecting: valve rods I and I5, and

crosshead 8 and memberIB in thenew position.

40 her I8 to slide to the right on plate I9 and to move slidevalves 6 and I4 to the right through valve rods I and, I5 and crosshead 8 through dis.-

taining cylinders 5 I, 52, 53, and 54, each of which V is preferably identical in design'with themechanism described-in Figure- 1; As shown in the Figure 2, one of the two discharge conduits of each cylinder, namely, conduit I0, is connected toaareturn conduit 59. whilethe other discharge conduitv namely,-conduit 9, is connected to the next cylinder except in the case of cylinder 7 54 wheres'aid other-discharge. conduit 9 is connected toza smalltest separator'56; Separator 55 is connectedrto areceivin'g tank S-l-by a conduit 53; and to-a gas-meter 33'by aconduit 64; Return conduit 59 is connected-to"mainflowline 34. 59, 55, and: 62' are appropriate check and regulating valves;-

Referringirto 'Figure 1, in operation fluid fromzahydrocarbon oil well enters" cylindrical 1 and i is! moving in the direction indicated by? Let us assume tance d. When valves 6 and I4 have again reached the position shown in Figure 1, with'ports 5 and I2 open and ports 4, and I3 closed, latch 2! drops againlinto recess 29 andlocks the valve mechanism in this position; Fluid now reenters theright'end of cylinder I through port 5 and conduit 2, comprising one cycle of operation of one cylinderunit of the device. I

Referring to Figure 2, let us assume it is de-' sired to sample and meter the componentparts of oil, water, and gas flowing from the Well C011? nected to well fiowline 3.3 and to make certain tests upon the oil and gas at predetermined conditions-of separation. Flowline is cut out of fiowl-ine 34.- by closing branch line and opening branch line 49, leaving branch lines 31,33, and 39 open, and closing branch lines 4!, 42, and 43. The'fluid in line 39 now all flows through flow test line 35. Fluid from flow 1ine 35 enters cylinder 5| through conduit 2. Cylinder 5| divides the fluidadmitted thereinto into two equal parts; the right end discharges fluid into conduit I9 and-the left end into conduit 9. Conduit IIl'discharges fluid into return line- 59, which conducts the fluid back into main flowline 34. Conduit 9'conductsthe fluid from the leftend of the cylinder to the inlet conduit of cylinder 52;. Cylinder 52 divides the fluid passing through con-v duit. 9 into two equal parts also, discharging one-halfintoreturn "line 59; and the other half into cylinder-53-. Anynumber of cylinderscon... nectedjinseries may be employed dependin upon 5 decreases in a geometric progression. For example, two cylinders would permit taking a sample which is an exact A of the initial quantity in weight and composition. Three cylinders would provide a sample of /8; four cylinder, e; five cylinders, and so on. If the sampling period is sufficiently long, the law of averages will operate to allow the composition of the sample to be quantitatively the same as that of the total fluid flow during the test period, and the weight to be the predetermined exact fraction.

In employing the system shown in Figure 2, the final sample enters the small separator 56 where the gas is separated from the oil and Water, The gas passes through conduit 64 to gas meter 63 where its volume is measured. The oil and water pass from separator 56 through conduit 58to receiving tank 51, where they are separated by gravity and their volumes are measured. By multiplying the weight of the components of the sample by the reciprocal of the fraction by which it was reduced, the weight of each component which flowed from the well during the test period is determined with a high degree of accuracy.

It is to be understood that th above form of my invention herewith shown and described is to be taken as a preferred example of the same and that various changes in size, shape, and arrangement or application may be resorted to without departing from the spirit of the invention, and further, that the theories of operation, as set out in this invention, although believed to be sound and workable, are not to be construed as the sole basis for operating this device. This device operates successfully whether or not upon the principles described herein, and is to be limited only by the appended claims. Further it is to be understood that the hrase a sample receptacle when used in the claims refers not only to a separator such as 56 but also to the succeeding cylinders such as 52, 53 and 54.

I claim:

l. A system of the character described comprising a fluid flow conduit; a plurality of means arranged in series for successively dividing fluid admitted into each of them into substantially equal parts, each of said means including a cylinder, a piston reciprocable within the cylinder, intake means including a valve operated by said piston at the end of each stroke thereof for alternately conveying fluid into each end of the cylinder, a fluid sampler line and a fluid discharge line connected to the cylinder, and means including a valve for alternately discharging fluid admitted into the cylinder through the fluid sam pler line and the fluid discharge line during each complete stroke of the piston, the intake means of the first cylinder of the series being connected to the flow conduit, the intake means of each succeeding cylinder of the series being connected to the fluid sampler line of each preceding cylinder of the series, the fluid discharge line of each cylinder communicating with the flow conduit down stream of the intake means of the first cylinder of the series, and a sample receiving receptacle connected to the fluid sampler line of the last cylinder of the series.

2. A system of the character described comprising a plurality of well flow lines adapted to transmit fluid produced by corresponding oil wells, a main flow line, a test flow line, valved means for placing the well flow lines into and out of communication with the main flow line and the test flow line as desired, a plurality of means arranged in series for successively dividing fluid transmitted into each of them into substantially equal parts, each of said plurality of means including a cylinder, a piston reciprocable Within the cylinder, intake means including a valve operated by said piston at each end of its stroke for alternately conveying fluid into each end of the cylinder, a fluid sampler line and a fluid discharge line connected to the cylinder, and means including a valve for alternately discharging fluid conveyed into the cylinder through the fluid sampler line and the fluid discharge line during each complete stroke of the piston, the intake means of the first cylinder of the series bein connected to the test flow line, the intake means of each succeeding cylinder of the series being connected to the fluid sampler line of each preceding cylinder of the series, the fluid discharge line of each cylinder communicating with the main flow line down stream of the connection of the test flow line with the main flow line, and a sample receiving receptacle connected to the fluid sampler line of the last cylinder of the series.

3. In an apparatus for obtaining representative samples of a flowing stream of fluid, a main flow line for said stream, a cylinder, a piston reciprocable within the cylinder, means including a valve for alternatively conveying fluid from the main flow line at a given point into each end of the cylinder, a fluid sampler line connected to one end of said cylinder, a sample receptacle connected to said fluid sampler line, a discharge line connecting the other end of said cylinder to said main flow line down stream of said given point, and means including a valve for alternately establishing communication between the cylinder and said sampler and discharge lines, whereby a given quantity of fluid from the main line is delivered in definite proportions to said sample receptacle and back into said main flow line.

4. In the combination of claim 3, each of said means including a valve includin means actuated by said piston for operating said valves.

CYRUS D. C'ANTRELL, JR. 

